Tuyere block



Aug. 30,1938. R. G. FELGER Er AL 2,128,355

TUYRE BLOCK Filed oct. 11, 1934 2 sheets-sheet 1 Aug. 3o, 193s.

R. G. FELGER ET AL TUYRE BLOCK Filed oct. 11, 1934 2 Sheets-Sheet 2 ATTORNEYS.

Patented Aug. 30, 1938 UNiTeo sTATss :PATENT TUYRE BLOCK Application October 11,

13 Claims.

present invention relates to tuyres used tc supply air from an air passage to a bed-of fuel used for heating boilers or the like, and particularly to tuyeres used in boilers or the like wherein the fuel is fed to the combustion chamber by meohanical fuel feeding means, such a-s automatic stokers or the like.

Tuyre blocks heretofore used have had a relatively short life due to burning of the block by the heat of combustion of the fuel. Such blocks become less eiicient for supplying air to the fuel :7n the combustion chamber as they deteriorate due -to such burning, until it is necessary to draw the fires, cool the combustion chamber and replace the burned blocks. It also has been observed that serious hres in the air supply ducts frequently were due to burning embers dropping through the tuyres which had become defective by reason of heat which had burned through ya portion of the shell of the block. Some prior attempts sought to overcome these difficulties by cooling the nose of the tuyre block with baiiied air currents passing through the block and thereafter discharging the air substantially horizontally of the block. Such structures caused excessive turbulence in the air stream and have a much shorter life and lower ehiciency than the block of our present invention.

It is an object of the present invention to v'pro- 30 vide a tuyre block which is so constructed that the air streams passing through the block are utilized to cool the nose portion of the block and are thereafter introduced, through relatively unrestricted air passages with the minimum of .turbulence, into the combustion chamber.

It is a further object of the present invention to provide a tuyre block -in `which lexcess metal at the nose portion has been removed and -its construction is such that the air passing through ,4 the Vinterior thereof is effective to cause a substantial cooling of the block.

It is a further object of the present invention to provide a tuyre block having a depending rib in the interior thereof which is effective .to conduct the heat from the surface of the block to the interior of the block and to transfer the heat to the air streams passing therethrough. The said rib is effective also to direct the air blast outwardly from the interior of the block, forwardly of the nose portion thereof and toward the thicker portions of the fuel bed.

It is a further object of the present invention to provide a tuyre block which is relatively sim.

ple to construct, economical to operate and-which 55 `has a relatively long life of service, being so con- 1934, .Serial No. 747,842

structed that a substantially unimpeded body of air-circulates through the block and is thereafter discharged'directly into the bo-dy of the .tuel to be burned.

Other `objects of lthis invention will appear in the following description `and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Fig. i -is a fragmentary view, partly .in side elevation and partly in vertical section, showing a combustion chamber equipped with a series of tuyres constructed in accordance with the present invention.

Fig. 2 is a view in perspective of one of the tuyre blocks embodying the present invention.

Fig. 3 is a top plan view of the tuyre block shown in Fig. 2.

Fig. 4 is an enlarged fragmentary view in side elevation of a tuyre block shown in the solid lline view, fragmentary views of the tuyre blocks di- ,'rectly adjacent thereto being shown in the broken line.

Fig. 5 isa sectional View taken substantially on the line A5 5 of Fig. 4 in the direction of the arrows.

Fig. 6 is a sectional View taken substantially on the .line 6-5 of Fig. 4 in the direction of the arrows.

T'he terms front, forward, and terms similar meaning when applied to the tuyre the present invention refer to those portions `the tuyre which -face the center of the combustion chamber.

Before explaining in detail the present invention .it -i-s to be yunderstood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the yinvention is capable ofvother embodiments and of being practiced or carrie-d out in various ways. Also it is to be understood that the phraseology or termionology employed herein is for the purpose `of description and not `of limitation, and it is not `intended to limit the invention claimed herein beyond the requirements of the prior art.

Referring to Fig. 1, tuyre blocks of the present invention each consists of a body portion l@ having Va stepped nose portion il and an inclined heel .portion I2. As shown in Fig. l, a plurality of separate tuyre blocks of the pre-sent invention are supported on an inclined tuyre block supporting base i3 by means of bolts (not shown) which extend through holes passing through lugs 55 Il and i5 (Fig. 5) formed on opposite interior sides of the walls. Rows of tuyre blocks are placed in the combustion chamber in tiers or layers on each side of the fuel passage or valleys It and communicate with the air ring or collar (not shown) through which air under predetermined substantially constant pressures (which may be varied in accordance with the amount of fuel to be burned) is supplied to the combustion chamber of the furnace or boiler. The tuyre block constructed in accordance with our present invention is provided with a plurality of ports or nozzles lll adjacent each stepped surface of the nose portion I I, each port II communicating with an air passage I8 which is dened by the interior of the sides of the body I, and a depending rib it. In contravention to the customary practice in the art, the nose portion of the tuyre block of the present invention is recessed as at 20 to provide a pocket in which the ash or other solid products of combustion will be retained to thereby form an insulating blanket at the point where the tuyre block is subjected to the greatest amount of heat, and the ports I'I discharge air streams which travel forwardly and outwardly at an angle to the center line of the tuyre on each side of the nose portion II.

The stepped nose portion I I is provided with a plurality of flat substantially horizontal fuel supporting surfaces or tables 2l. Each table 2l has an exposed surface 2Ia and a rearwardly extending portion 2 I'o located beneath the forward overhanging fuel supporting surface 2id of the next higher step of the block. This construction is such that if the nose portion or any part of the exposed table section 2id of any one of the successive steps of the block should burn through7 burning embers, ash or other material from the interior of the combustion chamber would drop through the b-urned-out portion and be caught on the supporting surface ZIoi of the table section directly beneath. Such material would tend to be blown back into the fuel bed by the air blast. In this manner the tuyre block of the present invention prevents foreign matter, such as burning embers, ash, or the like, from falling downwardly through the tuyres and into the air collar or chamber. We have found that this construction prevents many fires in the air chamber which occur in the use of tuyres of conventional design with consequent damageresulting to the air control mechanism.

The tuyres block of the present invention may be adapted to any particular type of combustion chamber design, one type of which is shown in the present drawings and comprises the tuyre block supports I3 which also act as the air blocks forming the connecting passageway between the tuyre blocks and the air collar. In this construction the heel portion I2 of the tuyre block is preferably provided with a rabbeted portion 22 which engages with a ledge on the air block and thus provides an effective seal which prevents leakage of air between the heel I2 of the tuyre and the tuyre support I3. The extended at surfaces provided on the bottom and top portions of each tuyre block are so arranged that when the blocks are placed in superimposed relation, the flat bottom surface of the top block cooperates with the flat top surface of the adjacent bottom block to effect an air seal which prevents any substantial leakage of air from between the adjacent blocks. j

The interior construction of each of the separate steps or tiers of the tuyre block is shown in Fig. v5. It will be there observed that therecessed portion 20 of the nose il is formed in direct integral connection with the rib I9 which extends rearwardly therefrom to the interior of the tuyre block. The rib I9 thus extends throughout the length of the inclined nose of the tuyre block and depends inwardly into the air chamber. The air passing from the air collar through the tuyre supporting air block impinges against the rib I9 and is divided into two streams which are directed forwardly and outwardly through the air passages I3. The axes of these passageways I@ preferably are curved outwardly at an angle of less than 90 to the center .line of the tuyre block in such a manner that the air blast is directed into the sides of the stream of fuel at points forwardly of the tuyre nose. (In a preferred form of the invention as here shown the center line of each of the passageways I8 extends outwardly at an angle of substantially 51 to the center line of the tuyre.)

In a typical installation of tuyre blocks embodying the present invention the blocks are placed in superimposed relation to form a. series of spaced tiers extending about the combustion chamber. These tiers are spaced a distance apart, preferably from twelve to eighteen inches. With this spacing of the tiers of the tuyres having the air streams discharged outwardly at an angle of approximately 51 to the center line of the tuyre, it has been found that the air streams from opposed tiers of tuyres intersect and converge in the spaces between the tiers of tuyres and forwardly of the noses thereof. These points of intersection and convergence of the air stream lie substantially in a plane which extends above and substantially parallel to the inclined plane of the nose portions of the tiers of tuyres. The angle of inclination of such planes will be found to vary for particular installations but by arranging the spaces between the tiers in accordance with the angle of inclination of the tiers and the angular direction imparted to the air stream by the air ducts, it will be found that a construction embodying the present invention will effect maximum burning of the fuel at points removed from the nose portion of the tiers.

It is known that fuel tends to burn at the greatest temperature at the point of maximum air supply. In order that this maximum temperature shall not be generated either at or below the plane of the nose of the tuyres, the present invention provides a construction wherein the maximum air supply is discharged into the fuel bed at points forwardly of the nose portions of the tuyres and above the plane thereof so that the maximum temperature resulting from the combustion of the fuel occurs at a distance from the nose portions of the tuyres. Such construction. also has been found to prevent any substantial burning of the fuel in the spaces between the tiers of the tuyres or substantially in the plane of the tuyre noses.

, The provision of the recessed portion Zil in the nose portion Il of each step of the tuyre block permits the elimination of surplus material in the nose portion which, if provided in an excess amount, results in the accumulation of excess heat at such points and a consequent burning of the metal. In the construction herein provided the amount of vmetal is such that the heat passing into the nose portion of the tuyre block is rapidly conducted into the rib I9 and radiated through the rib i9 to the air passing -through the air passages i8. At Ano -time is there any substantial accumulation lof 'heat in the -nose portion of 4the tuyre. The provision of the rib l-S thus not only effects the cooling of the nose I'I -of the tuyre block by carrying away the heat therefrom and dissipating it into the air stream, but a-lso acts "as a means for increasing the preheati'ng Iof the air prior to combustion as -it passes through the passages i8 and the port-s il'. This construction, because of the heating of the air in the substantia'lly unrestricted air passages, increases fits velocity during the passage therethrough just prior to discharge through the ports Il. It has been found that this tends to lessen the load on the air supply fan and secures a substantially greater penetration `of the air 'into the fuel bed than with other proposed constructions.

It will be observed that this construction is ysuch as to give substantially unimpeded air passages which permit the flow of air from the air `vcollar directly into the combustion chamber with a minimum of turbulence and without reversing the direction of the air stream. The vconstruction also imparts positive direction tothe air streams into the body of fuel at a point forwardly -of the tuyre Diiculties heretofore have been experienced with tuyre blocks of conventional construction due to the fact that the air passing through the tuyre lblock was baiiied in such a manner as Ato create considerable turbulence within the block and creating substantial back pressure on the air supply fan. Such construction also prevented a positive directing of the vair streams into the fuel bed at a predetermined point in advance of the tuyre. In a tuyre ofthe construction herein disclosed, the predetermined vpoint kat which 'the'air vis discharged into the fuel is a point removed from the ltuyres where `the fuel bed is relatively thick. It has been found that the fuel bed will vary in -depth due to load conditions from a few inches to as r'high in "some cases as two 'or three feet. The bed "at substantially all times is ordinarily thicker 'at certain regions laterally of or more remote from the tuyre, so that by virtue of the present invention a tuyre construction is provided which causes the air streams to be discharged into the portions of the fuel bed having the `greatest depth and las a consequence requiring the greatest penetration of the incoming air blast.

In testing the tuyre block of the present invention, it has been found that as compared `with ra -tuyre block of standard construction, vthe number of tuyre blocks replaced per thousand tons of fuel burned has been reduced from 3.2 to 0 overa period during which 32,000 tons of fuel 'were burned. Thus the present tuyre block will permit continuous operation of Vthe boiler for 'a greater period of time than the tuyre blocks of 'conventional design.

It also has been found that tuyre vblocks embodying the present invention show less tendency to Warp than tuyre blocks 'of conventional design This is largely due to the plurality of stepped ledges 2i and the reinforcing ribs I9.

While the present invention has been shown in a preferred embodiment in which a plurality of substantially horizontal fuel supporting surfaces are placed at the nose il in stepped relation to each other, it is to be understood that the number of ledges and the number of air ports which may be placed on any one of such blocks may be varied to conform to various operating conditions Thus, in contravention to the usual practice of providing single-step `tuyre blocks of box-`flike shape, our invention contemplates, when Iconsidered from one -of its broader aspects, .providing a novel 'tuyre block consisting of a plurality of forwardly -diverging curvilinear nozzles, the walls of which Ia-re mutually merging to provide the outside 'Walls-of t-he :block Yand the rearwardly `extending cooling rib, said block having surfaces which must be "exposed vto the action o'f 'the radiant heat reduced to -a min-imumand adapted to accumulate protective layers of ashes and to keep vsaid layers without permitting the air from the ports ror from leaking seams to blow them away, or lto promote burning of the fuel Ain close proximity to the block. Considered from another of its broader aspects, the present invention contemplates providing a novel "tuyre block in which the total amount of hea-t imparted to the -mass 1of the block per unit of time by radiation and conduction, balances the amount of heat given up lby said block to the air moving therethrough, at a suiiciently low tem perature, that is, at da temperature at `which no rapid burning-out of the metal results.

Tuyre blocks of the ypresent invention may be used -wi-th various types of Stoker vinstallations in the combustion chambers -of lboilers or lfurnaces and the 'present description, therefore, has been directed `lmore particularly to the tuyre unit itself, the particular types of -stokerconstructions beingwell'known to those lskilled in the art.

We claim:

-1. Atuyre block having apluralityof stepped substantially flat fuel supporting surfaces, an air passage extending through the interior thereof and having ldischarge nozzles beneath the fuel supporting portions and 'arranged to discharge 'air horizontally into -the 'body Aof fuel forwardly and laterally -of the tuyre block, each of said stepped substantiallyflat surfaces having a nose portion -recessed to yprovide a valle-y therein, a ret enforcing lrib-extending from said valley and into 'said air passage and having a formed surface adapted to Adeflect air outwardly through said' nozzles at kan angle, less than 90, to the center -line of the tu-yre..

l2. A tuyre block having interior W-alls and a portion forming -a substantial-ly horizontal fuel 'supporting surface, a recessed multiple-step nose vportion formed adjacent the forward edge thereof, a reenforcing rib depending downwardly therefrom and Aextending longitudinally thereof and forming with said interior walls of the block a pluralityo'f air nozzles terminating at one end "in ports adjacent the opposite edges yof said fuel supporting portion.

3. A @tuyre compri-sing in combination a hol- 'low shell having -a forwardly extending recessed multiplestep nose lportion and curvilinear nozz'les extending throug-h said shell on 'opposite sides of said nose portion and adapted to discharge streams of air into a fuel bed at points 'forwardly -of said recessed nose portion and at an `angle to the median line thereof.

4. A tuyre comprising in combination a hollow shell having `a rearwardly and vcentrally recesse'd 'nose portion of 'multiple-step construction and centrally partitioned nozzles extending through said shell on opposite sides of said nose portion and adapted to discharge streams of air into a fuel bed at points forwardly of said recessed nose portion and at an angle outwardly to the median line thereof.

5. A tuyre comprising in combination a hollow shell having a forwardly extending recessed nose portion of multiple-step construction, a depending rib of heat conducting material extending downwardly into said hollow shell on a line substantially co-extensive with the longitudinal median line of said nose portion, and nozzles extending through said shell on opposite sides of said depending rib, the inner walls of said nozzles merging smoothly into said rib, and said nozzles being adapted to discharge streams of air into a fuel bed forwardly of said recessed nose portion and at an angle outwardly to the center line of said nose portion.

6. A tuyre comprising a series of horizontal vertically spaced table sections receding upwardly in stepped relation and each terminating in a centrally recessed nose portion, a central partition dividing the space between each adjacent pa' of table sections into a pair of forwardly diverging air nozzles terminating in ports, said partitions being extended rearwardly to provide a common substantially continuous dividing wall longitudinally of the tuyre.

'7. A tuyre comprising a series of horizontal vertically spaced table sections receding upwardly in stepped relation and terminating in a centrally recessed nose portion of multiple-step construction, a central partition dividing the space between each adjacent pair of table sections into a pair of forwardly diverging air passages terminating in nozzles, said partitions being extended rearwardly to provide a single continuous dividing wall longitudinally of the tuyre and the mouth of each nozzle extending at least in part in advance of the base of the adjacent recessed portion.

8. The combination in a combustion chamber of a source of air supply, a series of unitary tuyre blocks arranged in spaced substantially parallel inclined tiers within said combustion chamber and communicating with Said source of air supply, each of the tuyre blocks having an indented nose portion of multiple-step construction, and air supply ducts discharging on opposed sides thereof and so arranged in said tiers that the tips of said indented nose portions lie substantially in a common inclined plane and the air streams from the opposed faces of the separate tiers of the tuyres intersect and converge in a plane lying above and substantially parallel to the inclined plane of the nose portions thereof.

9. A unitary tuyre block including a plurality of integrally formed air nozzles, said nozzles having curvilinear air passages adapted to discharge air forwardly and laterally at both sides yof the block, said nozzles being arranged in pairs, one pair above and rearward of the other, the nozzles in each individual pair being divergently disposed with relation to each other and forming in front of the block a forwardly extending shelf portion adapted to accumulate in operation a protective layer of ashes.

l0. A unitary tuyre block comprising a plurality of integrally connected air nozzles, said nozzles forming curvilinear air passages adapted to discharge air forwardly and laterally at both sides of the block, said nozzles being arranged in pairs, one pair above and rearward of the other, the nozzles in each individual pair being divergently disposed with respect to the vertical plane passed through the median line of the block, the outer side walls of the nozzles merging smoothly, one into another, to form the side walls of the block, the inner side walls of said nozzles similarly merging to form a rib extending rearwardly within the interior of said block along said vertical plane.

11. A unitary tuyre block comprising a plurality of integrally connected air nozzles, said nozzles forming curvilinear air passages adapted to discharge air forwardly and laterally at both sides of the block, said nozzles being arranged in pairs, one pair above and rearward of the other, the nozzles in each individual pair being divergently disposed with respect to the vertical plane passed through the median line of the block, the outer side walls of the nozzles merging smoothly one into another to form the side Walls of the block, the inner side walls of said nozzles similarly merging to form a rib extending rearwardly within the interior of said block along said Vertical plane, and the horizontal bottom walls of each pair of nozzles merging and extending forwardly between the nozzles of the pair to form an ash collecting shelf.

12. In combination, a pair of tuyre blocks superimposed in stepped relation, each block having a closed front wall of multiple-step construction extending centrally across the major portion of the forward face thereof, said blocks also having extended substantially plane contaciing walls adapted to engage in a substantially air-tight manner, whereby no air can emerge from the central portion of the front of either of said blocks nor from between said blocks near the central portion thereof, thus preventing burning of the fuel in close proximity of said blocks as well as preventing blowing away of the protective ash layers.

13. In combination, a pair of tuyre blocks superposed in stepped relation, each tuyre having plane top, bottom and side walls and a front wall including forwardly extending plane sections forming an angle with said side walls, said sections having apertures therein whereby to direct the air laterally and forwardly of said tuyre, said front wall also including a curvilinearly recessed portion connecting said sections, said blocks being superimposed with the plane sections of the front Wall of the upper tuyre spaced rearwardly of the corresponding sections of said lower tuyre, the plane top of the lower y,

tuyre extending forwardly of the front of the" 

